Flags representing individual officers and officials are either "positional colors" or "individual flags." The Corps of Engineers is not a major Army command, but a branch of service, and therefore has no organizational flag. It does have a "whole-branch" organizational color.

According to Chapter 3, Section III, AR 840-10 (The U.S. Army's flags regulation), the Chief of Engineer's flag is classified as a "Positional Color."

Chief of Engineers' positional color is a scarlet field with white fringe and the COE branch insignia--the twin-towered castle--in white.

The situation is somewhat complicated by the fact that the civil branch of the COE does use a scarlet flag with the insignia in white, sans fringe, as a vessel flag and as a distinguishing flag at non-military installations. This flag is also often flown at the headquarters of the post engineer on many Army installations, though regulations prohibit this.